Changing file extensions- XP Pro

OK, so I download a necessary update for my TV tuner card, follow instructions, and: "Windows cannot open this file because it does not know what program created it." Checking CKnow on the web brings no results. I bring up the driver wizard, type in the file name, and where to find it, and the wizard says: "there is no information about your device in this folder." ?????

I downloaded the file multiple times, and under "properties," it lists the KB of the file size, so I know the info is in there.